FIELD OF THE INVENTION
[0001] The present invention relates to an apparatus and process for removing an end portion
of the shielding foil of a shielded electric cable. The present invention is used
in the field of shielded electric cables and particularly in the field of bipolar
cables.
KNOWN PRIOR ART
[0002] Shielded electric cables comprising one or more conductors dielectrically insulated
and provided with one or more shielding layers made of electrically conducting material,
which act as an electromagnetic shield to cancel or at least limit electromagnetic
interference (EMI), are known.
[0003] Cables (e.g. coaxial cables) having a single central conductor usually made of copper,
wrapped in a layer of electrically insulating material (a dielectric) usually made
of polyethylene or PTFE, which separates the central core from one or more outer shielding
layers, are known.
[0004] Generally, the shielding layer comprises a shielding foil of conductive material
(known in the art by the English term "foil"), e.g., a thin, preferably multilayer,
aluminum-based film that wraps around the layer of electrically insulating material,
and a shielding braid that wraps around this underlying foil. There is also an outer
cable-insulation sheath that encloses the layers and components described above.
[0005] Also bipolar cables, which have two adjacent conductors, each individually wrapped
in a respective layer of electrically insulating material (a dielectric), and one
or more shielding layers which generally comprise a shielding foil covering the assembly
of the two conductors, which are individually wrapped in the layer of electrically
insulating material, are known.
[0006] Such bipolar cables also have a shielding braid composed of strands, which surrounds
this shielding foil made of conductive material.
[0007] As known, the shielding metal foil can be made, for example, of a preferably multi-layered
aluminum-based foil having different thicknesses, usually between 0.05 mm and 0.3
mm, though not limited thereto, which is arranged around the dielectric that covers
the conductor (or in general one or more conductors) of the shielded electric cable.
[0008] In other words, the foil, constituting an additional shielding of the cable, is generally
interposed between the electrically insulating material (dielectric) and the braid.
[0009] As mentioned above, there is a protective sheath usually made of an electrically
insulating material on the outside of the shielding braid.
[0010] The shielded electric cables may be further provided with electric connectors connected
to the ends of the electric cable. For example, in order to constrain a connector
to the end portion of a coaxial or bipolar cable, the end portion of the electric
cable must be prepared by carrying out a process which typically comprises the following
steps:
- removing a portion of the outer protective sheath, so as to leave a predetermined
length of the shielding braid exposed at an end portion of the electric cable;
- removing or overturn backwards (i.e., in the opposite direction with respect to the
free end or end portion of the cable which is under operation) a portion of the exposed
shielding braid, in order to shorten the exposed portion of shielding braid so as
to obtain the final part of the cable end portion with the shielding foil exposed;
- removing a portion of the shielding foil, to shorten the exposed portion of shielding
foil so as to obtain the final part of the cable end portion with the dielectric exposed.
[0011] Removing the shielding foil is a crucial operation in the process of preparing the
end portion of a shielded electric cable.
[0012] Some processes pertaining to the known art, such as the one described for example
in
JP2019208322, carry out the removal of the shielding foil by applying an air jet to the outer
surface of the end portion of the cable.
[0013] The shielded cable is inserted into a cone-shaped support cavity and the end portion
comprising the shielding foil to be removed is inserted into a stripping cavity adjacent
to, and coaxial with the cone-shaped cavity in which the cable is retained.
[0014] The apparatus comprises a channel (parallel to the stripping cavity) to supply air
into the stripping cavity through ducts that branch off transversely from the air
supply channel to deliver air into the stripping cavity towards the end portion of
the cable. In a second embodiment, air can be injected in the central duct of the
stripping cavity.
[0015] In addition, the apparatus has cutting blades arranged between the insertion portion
and the stripping portion to sever the shielding foil.
[0016] In this regard, the process according to
JP2019208322 provides for rotating the cable and the apparatus relative to each other about the
axis of the cable so as to determine the cutting of the foil and separation from the
cable.
[0017] The foil removal obtained by means of this process may be nonuniform, that is, the
cutting profile of the foil is nonuniform in the circumferential direction because
it depends on the displacement of the foil towards the blades, which can be highly
variable from one operation to the next and therefore not very precisely repeatable.
[0018] In addition, a disadvantage arising from such an apparatus is the fact that waste
portions of the foil, e.g., scraps, may remain in the apparatus, for example in the
stripping cavity or in the air ducts.
[0019] In addition, the operations are complicated by the need to insert the cable into
the support and stripping cavities, in fact, they require the cable to be inserted
into the closed section of these elements. This operation may cause an undesirable
contact resulting in deformation of parts of the cable, such as the shielding foil
with the inner walls of the cavity in which it is inserted, thereby jeopardizing the
subsequent removal operations.
[0020] Furthermore, the shape of the support and stripping cavities is unsuitable for use
with non-circular shaped cables, such as cables of the bipolar type, which do not
have a perfectly circular section.
[0021] Object of the present invention is to overcome the drawbacks of the art and to provide
a process and an apparatus for preparing the end portion of a shielded electric cable
capable of carrying out the removal of the end portion of the shielding foil with
high degree of precision, thereby achieving a clean and homogeneous cutting profile.
[0022] Further object of the present invention is to provide a process and apparatus for
preparing the end portion of a shielded electric cable capable of carrying out the
removal of the shielding foil uniformly and without the risk of damaging the foil
and/or conductor(s) of the shielded electric cable.
[0023] Further object of the present invention is to provide a process and apparatus for
preparing the end portion of a shielded electric cable which is capable of carrying
out the removal of the shielding foil and which is simple and inexpensive to make.
[0024] Further object of the invention is to provide a process and apparatus for removing
the shielding foil of a shielded electric cable that is versatile and can be used
in combination with different types of shielded cable, particularly with multipolar-type
cables.
SUMMARY OF THE INVENTION
[0025] These and other objects are achieved by the present invention by means of an apparatus
for removing the end portion of the shielding foil of a shielded electric cable according
to the independent claim 1 and a process according to the independent claim 16.
[0026] Additional features/aspects of the present invention are described below and/or set
forth in the dependent claims. From the very beginning, it should be noted that what
described and/or claimed herein referring to the process may be applied to the apparatus
and vice versa.
[0027] The apparatus for removing an end portion of the shielding foil of a shielded electric
cable, wherein an end portion of the cable has at least one shielding foil covering
at least one conductor provided with a layer covering the shielded electric cable
(in other words, the shielding foil is placed outside the insulating covering layer
the at least one conductor is equipped with), and wherein at least one end portion
of the shielding foil is exposed, comprises:
positioning means for positioning the shielding foil in at least one tensioning position,
axially moving means adapted to operate a relative tensioning motion in the axial
direction with respect to said cable, between the positioning means and the cable
to cause the tensioning of the end portion of the shielding foil and thus to cause
said tensioning position to be reached,
cutting means provided with a cutting surface, the apparatus further comprising radially
moving means configured to move said cutting means, preferably at least along a radial
direction with respect to the longitudinal axis of the cable, with respect to the
foil placed in a tensioning position to carry out the cutting of the foil.
[0028] It should be noted that the expressions "tensioning position" and "tensioning of
the end portion of the shielding foil" mean the condition, or state, in which the
end portion of the shielding foil is tensioned. In other words, these expressions
are intended to mean the tensioned condition, or state, of the foil and, in particular,
the condition, or state, caused in the end portion of the foil by the application
of a tensile force.
[0029] Advantageously, the apparatus according to the invention allows the shielding foil
to be removed uniformly and without the risk of damaging the foil and/or the conductor(s)
of the shielded electric cable.
[0030] In fact, the movement of the positioning means allows the foil to be tensioned and,
in particular, to reach a tensioning position in which the foil is in a tensioned
state. The term "tensioning movement" will also be used in this description to refer
to the relative motion between the positioning means and the cable that results in
the tensioning of the end portion of the shielding foil, preferably by the application
of a tensile force.
[0031] Such a tensioning position, in which the foil is under tension, is particularly suitable
for carrying out the cutting operations.
[0032] According to an aspect, the apparatus comprises radially moving means configured
to move the positioning means along a radial direction with respect to the longitudinal
axis X of the cable, between a closed position to engage the outer surface of the
shielding foil of the cable and an open position in which the cable is released from
the positioning means.
[0033] According to an aspect, the end portion of the shielding foil is retained by the
positioning means at least during the tensioning movement.
[0034] Specifically, according to an aspect, the positioning means are shaped to retain
the cable at least during the tensioning movement and during cutting.
[0035] It should also be noted that, according to an aspect of the present invention, in
the case where foil removal is carried out by the positioning means, the shielding
foil is retained by the positioning means even during the further movement of foil
removal.
[0036] According to an aspect of the present invention, the positioning means are displaced
by the moving means by a travel that is selected so as to bring the foil into a tensioning
state.
[0037] According to an aspect, this tensioning stroke is between 0.2 mm and 3 mm. In other
words, the desired tensioning of the shielding foil can be determined by means of
a travel, or displacement, for example between 0.2 mm and 3 mm, preferably measured
in the axial direction (i.e., according to a direction X' parallel to or coincident
with the axis X of the cable) also appropriately selected according to the thickness
of the foil and its own elastic characteristics.
[0038] Advantageously, according to the present invention, the effective cutting of the
shielding foil and its subsequent removal is achieved simply and economically by tensioning
the foil by a limited tensioning stroke or displacement operated by the foil positioning
means, thus requiring inexpensive and uncomplicated components.
[0039] In fact, a limited travel or displacement appropriately selected in relation to the
nature of the shielding foil from its physical and morphological state, e.g., a travel
according to the claimed range, is sufficient to obtain effective tensioning of the
foil, which, as mentioned above, allows a subsequent clean cut to be achieved.
[0040] Compared with the apparatuses of the known art and in particular those using only
an air jet for removing the foil, the apparatus according to the present invention
is much more effective and precise.
[0041] According to an aspect of the present invention, the positioning means are movable
to make an additional travel greater than the tensioning stroke, to cause the removal
of the end portion of the shielding foil.
[0042] Therefore, advantageously, in the case where the foil removal is carried out by the
positioning means, the shielding foil is retained by the positioning means that are
displaced by the axially moving means by an additional travel greater than the tensioning
stroke, to cause the removal of the end portion of the shielding foil from the cable.
[0043] It should be noted that the axially moving means cause a relative motion, in the
axial direction with respect to the cable, between the positioning means and the cable
to cause the tensioning of the end portion of the shielding foil. Advantageously,
the relative movement of the positioning means with respect to the cable allows the
foil to be subjected to a tensile force, preferably in the axial direction, which
results in the effective tensioning thereof.
[0044] It should be noted that axial motion means a movement along a direction that is parallel
or coincident to the longitudinal axis of the cable. However, movements of the positioning
means according to directions inclined with respect to the cable axis, which still
allow a tensile action to be transmitted on the shielding foil, thus determining the
tensioning thereof, are not excluded.
[0045] According to an aspect, the contacting surface of the positioning means with the
end part of the shielding foil of the positioning means is configured to provide the
anchorage and/or an increase in the coefficient of friction as well as an increase
in the localized pressure, and preferably the contacting surface comprises a surface
discontinuity and/or a material with a high coefficient of friction.
[0046] For example, the surface discontinuity is obtained by machining that creates surface
discontinuities and/or by interposing a material that increases the coefficient of
friction.
[0047] Advantageously, the positioning means are shaped so as to retain the cable to be
processed at least during the tensioning movement and during cutting and, in the case
where foil removal is carried out by the positioning means, the foil is retained by
the positioning means also during the further relative movement with respect to the
cable to cause the foil to be separated from the end of the cable and here the removal
thereof.
[0048] According to an aspect, the shape of such elements, which will be better described
below, provides a locking/retaining surface to lock/retain the cable that is substantially
complementary to the shape of the latter so as to retain it with extreme precision,
without excessively compressing the conductor wrapped inside the foil.
[0049] According to an aspect, in the closed position (and thus the one in which the foil
is retained), the surface contacting the end portion of the shielding foil of the
positioning means delimits an opening substantially complementary to the section of
the end portion of the cable comprising the end portion of the shielding foil which
covers the at least one conductor.
[0050] According to one aspect, the cutting surface of the cutting means has a profile which
is substantially complementary to the profile of the outer surface of the shielding
foil covering both the at least one conductor and the covering layer with which it
is equipped and/or to be substantially complementary to the profile of the outer surface
of the covering layer of the at least one conductor.
[0051] Advantageously, according to this aspect, the shape of the cutting surface, preferably
complementary to the profile of the outer surface of the foil and/or complementary
to the profile of the outer surface of the covering layer of the at least one conductor,
allows the foil under tension to be torn and/or cut by the positioning means with
a homogeneous cutting profile, without damaging the underlying conductor.
[0052] It should be noted that the term "substantially complementary" is used herein to
mean that the profile of the cutting surface follows (at least in part, preferably
along its full extent and then completely) the profile of the outer surface of the
foil and/or the outer surface of the covering layer of the at least one conductor.
[0053] According to an aspect, the profile of the cutting surface has a shape similar (in
the sense of geometric similarity) to the profile of the outer surface of the foil
and/or the profile of the outer surface of the covering layer of the at least one
conductor.
[0054] According to an aspect, in the closed position, the cutting surface of the cutting
means has a profile (or perimeter) that is substantially complementary to the profile
(or perimeter) of the end portion of the cable, comprising the end portion of such
shielding foil covering said at least one conductor.
[0055] In particular, according to this aspect, in the closed position, the cutting surface
of the cutting means has a profile (or perimeter) substantially complementary to the
profile (or perimeter) of the outer surface of the shielding foil and/or the profile
(perimeter) of the outer surface of the covering layer of the at least one conductor.
[0056] In other words, according to an aspect, in the closed position, the cutting surface
of the cutting means forms a closed perimeter or profile that delimits an opening
within which the cable is placed. The section delimited by the profile of the cutting
surface of the cutting means substantially corresponds (preferably has a similar shape)
to the section of the end portion of the cable (according to a plane perpendicular
to the cable axis) comprising the end portion of this exposed shielding foil covering
said at least one conductor.
[0057] In more detail, according to an aspect, the section delimited by the profile of the
cutting surface of the cutting means substantially corresponds (preferably has a similar
shape) to the section of the end portion of the cable (according to a plane perpendicular
to the cable axis) delimited externally by the outer surface of the exposed shielding
foil or delimited externally by the outer surface of the covering layer of the at
least one conductor.
[0058] According to an aspect, the cutting surface of the cutting means comprises at least
one curved surface.
[0059] Advantageously, the presence of an at least partially curved shape of the cutting
surface allows the tearing and/or cutting of the foil, which is effectively subjected
to tension due to the fact that the cutting profile is configured similarly to the
shape of the outer surface of the shielding foil, which has an at least partially
curved surface due to its arrangement on the at least one conductor of the cable.
[0060] Advantageously, according to such a configuration, the apparatus is adapted to process
cables of the coaxial type and such a curved cutting surface is shaped to be complementary
to the profile of the outer surface of the shielding foil, so as to optimally surround
the latter in the closed position.
[0061] According to an aspect, the cutting surface of the cutting means comprises at least
one protruding element, or tooth.
[0062] According to an aspect, the cable comprises two preferably adjacent conductors and
the cutting surface of the cutting means is configured to be substantially complementary
to the profile of the outer surface of the shielding foil covering said preferably
adjacent conductors, which are each equipped with a covering layer, and/or to be substantially
complementary to the profile of the outer surface of the covering layer of the two
conductors.
[0063] Preferably, according to an aspect, the cutting surface of the cutting means has
a profile substantially formed by the intersection of two circumferences intersecting
each other.
[0064] Advantageously, according to such a configuration, the apparatus is adapted to process
cables preferably of the bipolar type, and such a cutting surface that has a profile
formed by the intersection of two intersecting circumferences is formed to be complementary
to the profile of the outer surface of the shielding foil wrapping the two adjacent
conductors and/or to be complementary to the outer surface of the covering layer of
the two adjacent conductors, so as to optimally enclose (surround) the foil in the
closed position.
[0065] However, the application with cables having a larger number of conductors is not
excluded. In these possible embodiments, the cutting surface is appropriately shaped
to be complementary to the profile of the outer surface of the shielding foil wrapping
the cable conductors and/or to be complementary to the outer surface of the covering
layer of the conductors, so as to optimally enclose (surround) the foil in the closed
position.
[0066] According to an aspect, the cutting means are moved by the moving means, preferably
in a radial direction with respect to the cable, between a closed position to engage
the outer surface of the shielding foil and an open position in which the cable is
released from the cutting means.
[0067] Specifically, the cutting means are moved by the moving means, preferably in the
radial direction with respect to the cable, between a closed position in which the
cutting surface surrounds the outer surface of the shielding foil that covers the
at least one conductor equipped with a covering layer, and an open position in which
the cable is released from the cutting means.
[0068] It should be noted that the term surrounds is used herein to mean that, according
to possible embodiments, it is not excluded that at least part of the profile of the
cutting surface may possibly be placed at a distance from the surface of the foil.
[0069] According to an aspect, the apparatus comprises axially moving means adapted to operate
a relative motion between the cutting means and the cable, in an axial direction with
respect to the cable, in order to cause the end portion of the shielding foil to be
removed.
[0070] It should be noted that axial motion means a movement along a direction that is parallel
or coincident to the longitudinal axis of the cable. Advantageously, the apparatus
allows the shielding foil to be removed uniformly and without the risk of damaging
the foil and/or the conductor(s) of the shielded electric cable.
[0071] According to this aspect, the end portion of the shielding foil is removed by the
relative motion between the cutting means and said cable, operated by the axially
moving means in the axial direction with respect to the cable, and/or by the relative
motion between the positioning means and the cable, operated by the axially moving
means in the axial direction with respect to the cable.
[0072] Advantageously, it therefore happens that the end portion of the shielding foil is
removed by the cutting means and/or the positioning means, thus by a separate (or
simultaneous and synergical) action of the cutting means and the positioning means.
[0073] Advantageously, in the apparatus according to the present invention, thanks to the
action of tensioning the shielding foil (which is preferably made in the form of a
multilayer thin film) operated by the positioning means, it is possible to make effective
the subsequent cutting operation operated by the cutting means which, acting on the
shielding foil in a tensioned condition, results in a clean cut of the latter.
[0074] The subsequent relative movement between the cutting means and the cable, and/or
between the positioning means and the cable, allows the previously cut foil to be
removed and thus to be separated from the cable in a certain, simple and effective
way even on cables equipped with more than one conductor.
[0075] The removal of the shielding foil is defined as the separation of the foil portion
of the cable end, and, as mentioned above, such removal can be advantageously accomplished
quickly and easily by the movement of the cutting means or by a further movement of
the positioning means (previously moved for tensioning the foil), or by a combination
thereof.
[0076] According to an aspect, the radially moving means are configured to move these positioning
means with respect to the cable, preferably at least along a radial direction with
respect to the longitudinal axis X of the cable.
[0077] According to an aspect, in case the foil removal is carried out by the cutting means,
during the relative motion preferably in the axial direction between the cutting means
and the cable, the end portion of the foil is retained by the cutting means.
[0078] It should be noted that the expression "end portion of the foil is retained by the
cutting means" is intended to mean that, during the preferably axial movement, the
cutting means allow the portion of the shielding foil to be dragged and thus removed
(separated) from the cable.
[0079] According to an aspect, the apparatus comprises at least one pressurised air source
adapted to deliver pressurised air to said end portion, such that the pressurised
air exerts a force on said end portion of said at least one shielding foil to push
it towards said cutting surface of said cutting means.
[0080] Advantageously, by means of the present apparatus, the axial movement of the cutting
means allows the foil to be completely removed. In fact, in case the tearing operation
of the foil, which can be operated by the cutting means due to the action of the air
flow acting on the foil, is not sufficient to carry out the complete detachment of
the foil, the axial translation of the cutting means with respect to the cable allows
the removal of the non-torn end portion of the foil, which is opened by the pressurised
air flow and preferably retained by the cutting means.
[0081] Advantageously, in the apparatus according to the present invention, the action of
the pressurised air flow delivered on the shielding foil and the relative movement
in the axial direction between the cutting means and the cable allows the foil to
be removed and thus separated from the cable in a certain, simple and effective manner
even on cables equipped with more than one conductor.
[0082] As will be discussed more fully below, according to an aspect of the invention, the
action of pressurised air pushing the foil against the cutting means (to determine
its opening and to hold it against the cutting means) is combined with the relative
axial movement between the cutting means and the cable.
[0083] It should be noted that the term "combined" is intended to mean that the action of
the air flow and the relative axial motion can be performed in succession (and thus
performed at two separate times but cooperating with each other by being performed
in succession), or they can be performed simultaneously with the air flow acting on
the foil for at least part of the axial movement, preferably the entire duration thereof.
[0084] In addition, the axial movement of the cutting means in the axial direction overcomes
the drawbacks of the apparatus according to
JP2019208322 in which the operation of removing the shielding foil is carried out by delivering
pressurised air into the cavity in which the cable is inserted, which causes the foil
to be displaced towards the blades with the consequent problems of uncertainty of
the accuracy of the cut performed and repeatability of the operation.
[0085] In addition, unlike the process according to
JP2019208322, which provides for rotating the cable and the stripping apparatus relative to each
other and which has the consequent disadvantage that it cannot be used (or is in any
case ineffective) on cables with more than one central conductor (e.g. bipolar cables),
according to the present invention the relative axial movement allows the removal
of the foil to be carried out in a certain, simple and effective manner even on bipolar
or multipolar cables.
[0086] According to an aspect, the pressurised air source delivers air at a pressure between
2 bars and 80 bars, with preference for pressures tending to the higher value. According
to possible embodiments, the delivered air has pressure between 30 bars and 80 bars,
preferably between 40 bars and 80 bars.
[0087] According to a further aspect, the cutting means in the closed position form a continuous
wall extending around the cutting surface. Advantageously, the air flow delivered
by the pressurised air source allows the foil to be pushed, resulting in the opening,
on the continuous wall of the cutting means extending around the cutting surface.
[0088] According to an aspect, the end portion of the shielding foil is removed by the combined
action of the pressurised air jet and the relative motion operated by the axially
moving means, between the cutting means and the cable and/or the relative motion operated
by the axially moving means, between the positioning means and the cable.
[0089] Advantageously, the delivery of pressurised air towards the end portion of the cable
and the simultaneous axial translation of the cutting means with respect to the cable
axis, cooperate to create an adhesion force between the end portion of shielding foil
and the cutting means, so as to optimally push the foil end portion towards the cutting
surface of the cutting means, thereby allowing the foil end portion to be homogeneously
and optimally removed.
[0090] According to an aspect, the apparatus comprises a cable locking device adapted to
hold the cable in a fixed position during processing.
[0091] In particular, the cable can be effectively retained in a fixed position by the locking
device, such as a clamp, during the tensioning of the foil, for example by holding
the cable in a fixed position and displacing the positioning means to the closed (i.e.
foil retaining) position away from the cable, so as to cause the tensioning of the
foil, for example by applying a tensile force on the foil itself.
[0092] According to an aspect, the apparatus comprises a suction device for suctioning the
end portion from the shielding foil that is torn and removed.
[0093] Advantageously, such an air suction device allows for the complete removal of the
severed portion of the foil, thus preventing the accumulation of offcuts and scraps
which, after processing, could remain attached to the end portion of the cable and/or
to components of the apparatus such as the cutting means or the positioning means.
[0094] The present invention is also directed to a process according to claim 22, for removing
an end portion of the shielding foil of a shielded electric cable by means of an apparatus
according to the invention, wherein the end portion of the cable has a shielding foil
covering at least one conductor equipped with a covering layer (the foil is thus placed
outside the covering layer of the conductor), wherein at least one end portion of
the shielding foil is exposed for processing.
[0095] The process comprises the following steps:
- a) moving the positioning means of the shielding foil into at least one tensioning
position, by means of a relative tensioning motion, in an axial direction with respect
to the cable, between the positioning means and the cable to cause the tensioning
of said end portion of the foil;
- b) moving said cutting means towards this shielded electric cable, preferably in a
radial direction with respect to the longitudinal axis of the cable, until a closed
position of the cutting means around the shielding foil is reached, so that the cutting
surface of the cutting means surrounds and/or engages the outer surface of the foil
covering the at least one conductor to carry out the cutting of the foil.
[0096] Advantageously, according to an aspect, by tensioning the shielding foil, the cutting
means are able to carry out optimal cutting of the foil and thus its subsequent effective
removal from the cable.
[0097] According to an aspect, wherein the apparatus comprises axially moving means adapted
to operate, in an axial direction with respect to the cable, a relative motion between
the cutting means and the cable, in order to cause the end portion of the shielding
foil to be removed, the process comprises the further step c) of operating a relative
motion between the cutting means placed in a closed position around the shielding
foil and the cable, preferably in an axial direction with respect to the cable, to
cause the end portion of the at least one shielding foil to be removed and/or the
step of operating a relative motion between the positioning means and the cable, preferably
in an axial direction with respect to the cable, to cause the end portion of the at
least one shielding foil to be removed. Advantageously, as described above with reference
to the apparatus, the foil can be effectively removed (and thus separated from the
cable) after cutting while the foil is in a tensioned state, by separate or simultaneous
action of the cutting means or displacement means which are moved, with respect to
the cable, in order to ensure a complete detachment of the end portion of shielding
foil.
[0098] According to an aspect, wherein the apparatus comprises at least one pressurised
air source adapted to deliver pressurised air towards the end portion, such that the
pressurised air exerts a force on the end portion of the at least one shielding foil
to push it towards the cutting surface of the cutting means, the process comprises
the step (d) of delivering pressurised air by means of the pressurised air source
towards the end portion of the cable, such that the pressurised air exerts a force
on the end portion of the shielding foil to push it towards the cutting surface of
the cutting means thus ensuring adhesion of the shielding foil against the surface
of the cutting means.
[0099] According to an aspect, pressurised air is delivered along an axial direction defined
by the longitudinal axis of said cable, to hit the cable front and generate the opening/detachment
of the foil from the insulated conductors.
[0100] According to an aspect, at least part of step (c) is carried out during step (d).
[0101] Advantageously, the delivery of pressurised air towards the end portion of the cable
and the simultaneous axial translation of the cutting means with respect to the cable
axis, cooperate to create an adhesion force between the end portion of shielding foil
and the cutting means, so as to optimally push the foil end portion towards the cutting
surface of the cutting means, thereby allowing the foil end portion to be homogeneously
and optimally removed.
[0102] According to an aspect, the step (c) provides for moving the cutting means in an
axial direction with respect to said cable at least in the direction opposite the
delivery direction of pressurised air delivered by said pressurised air source.
[0103] Advantageously, this action ensures a complete detachment of the end portion of shielding
foil.
[0104] According to an aspect, the process comprises, prior to step (a), a step (a') of
moving such positioning means towards the shielded electric cable, preferably in a
radial direction with respect to the longitudinal axis of the cable, until a closed
position of the positioning means around the at least one shielding foil is reached
in order to ensure the centering of the at least one conductor covered with the at
least one shielding foil.
[0105] According to an aspect of the present invention, the positioning means are displaced
by the moving means by a travel that is selected so as to bring the foil into a tensioning
state. According to a possible embodiment, this tensioning stroke is between 0.2 mm
and 3 mm.
[0106] In other words, the desired tensioning of the shielding foil can be determined by
means of a travel, or displacement, for example between 0.2 mm and 3 mm, preferably
measured in the axial direction (i.e., according to a direction X' parallel to or
coincident with the axis X' of the cable) also appropriately selected according to
the thickness of the foil and its own elastic characteristics.
[0107] According to an aspect, the step a) provides for moving the positioning means, preferably
in an axial direction, with respect to the cable at least towards the free end of
the cable.
[0108] Advantageously, such movement allows the shielding foil to be effectively and rapidly
tensioned.
[0109] According to an aspect, the step a) provides for moving the positioning means by
a travel that is selected in such a way as to bring the foil into a tensioning state.
According to a possible embodiment, this tensioning stroke is between 0.2 mm and 3
mm.
[0110] In other words, the desired tensioning of the shielding foil can be determined by
means of a travel, or displacement, for example between 0.2 mm and 3 mm, preferably
measured in the axial direction (i.e., according to a direction X' parallel to or
coincident with the axis X of the cable) also appropriately selected according to
the thickness of the foil and its own elastic characteristics.
[0111] According to an aspect, after the step c), the process comprises the further step
of moving the positioning means with respect to said shielded electric cable, preferably
in a radial direction with respect to the longitudinal axis of the cable, until an
open position of the positioning means is reached, in which the cable is released
from the positioning means.
[0112] According to an aspect, the process provides a further step of moving the cutting
means with respect to the shielded electric cable, preferably in a radial direction
with respect to the longitudinal axis of the cable, until an open position of the
cutting means is reached, in which the cable is released from the cutting means.
[0113] According to an aspect, the process comprises a further step of suctioning the end
portion removed from the shielding foil and/or the step of delivering pressurised
air in order to remove any residue from the cable or from the apparatus components.
BRIEF DESCRIPTION OF THE FIGURES
[0114] Further characteristics and advantages of the present invention will be more evident
from the following description, which is made by way of example, with purely indicative
and non-limiting reference to the schematic drawings shown in the accompanying figures,
in which:
- figures 1A and 1B schematically show side views of the ends of a bipolar cable and
a coaxial cable, which can be machined with the apparatus and process according to
the present invention;
- figure 1C shows the section, according to a plane perpendicular to the axis, of a
bipolar cable according to figure 1A;
- figures 2A and 2B schematically show a portion of a cable that can be machined in
an apparatus according to the invention, comprising a shielding braid;
- figure 3 schematically shows a perspective view of a possible embodiment of the apparatus
according to the invention;
- figure 4 schematically shows a perspective view of a possible embodiment of the apparatus
according to the invention, during a possible step of the process according to the
invention in which the positioning means were moved towards the shielded electric
cable until a closed position around the shielding foil of the cable was reached,
and from this position the positioning means are moved in an axial direction with
respect to the cable for tensioning the foil;
- figure 5 schematically shows a perspective view of the apparatus according to the
invention during a possible step of the process according to the invention, in which
the cutting means are in closed position around the shielding foil under tension;
- figure 6 schematically shows a perspective view of the apparatus according to the
invention during a possible step of the process according to the invention, in which
the cutting means and the positioning means arranged in a closed position around the
shielding foil are moved in an axial direction with respect to the cable, to cause
the end portion of the shielding foil to be removed;
- figure 7 schematically shows a perspective view of the apparatus according to the
invention during a possible step of the process according to the invention, in which
the cutting means and the positioning means are moved with respect to the shielded
electric cable until an open position is reached in which the cable is released from
the cutting means;
- figure 7A schematically shows a perspective view of the apparatus according to the
invention during a possible step of the process according to the invention, in which
pressurised air is delivered to the end portion of the cable, so that the end portion
of the shielding foil is push towards the cutting means;
- figure 7B schematically shows a perspective view of the apparatus according to the
invention during a possible step of the process according to the invention, in which
the cutting means placed in a closed position around the shielding foil are moved
in an axial direction with respect to the cable, to cause the end portion of the shielding
foil to be removed;
- figure 8 schematically shows a perspective view of the apparatus according to the
invention, in which the moving means of the positioning means and of the cutting means
as well as the moving means for the axial relative motion between the cable and the
cutting means and the positioning means are also schematically visible;
- figures 9a and 9b are a perspective view and a detail plan view, respectively, in
the main extension plane of the positioning means in closed position;
- figures 10a and 10b are two plan views in the main front and rear extension plane
of the cutting means in closed position.
EMBODIMENTS OF THE INVENTION
[0115] Referring to figures 1A and 1B, a shielded electric cable 1 typically comprises at
least one central conductor 2, 20 and a shielding braid 4 separated by a layer of
electrically insulating material 5, 50, or dielectric, that covers the conductor or
conductors 2, 20. As mentioned, an additional shielding layer consisting of a shielding
foil 3, preferably a thin multilayer film made, for example, from aluminum, is arranged
between the braid 4 and the dielectric 5, 50.
[0116] For the sake of simplicity, in this document reference will be made only to the conductor
2, 20 of the cable, this term also referring to the covering layer 5, 50 of electrically
insulating material with which it is equipped. In fact, the expression "the foil 3
covers the conductor 2, 20" will be used to mean that the foil is placed externally
with respect to the insulating covering layer 5, 50 with which the at least one conductor
2, 20 of the cable 1 is equipped.
[0117] Around the shielding braid 4 there is an outer protective sheath 6, also typically
made of electrically insulating material.
[0118] In a possible embodiment shown in figure 1A, the apparatus schematically denoted
in the figures as a whole by the numerical reference 10 is adapted to process a cable
1, of the bipolar type, comprising two adjacent conductors 2, 20 each individually
wrapped in a respective layer of electrically insulating material (for example a dielectric)
5, 50, and a shielding foil 3 which covers the assembly of the two conductors 2, 20,
which are individually wrapped in the respective layer of electrically insulating
material 5, 50.
[0119] In an embodiment, the apparatus 10 comprises a locking device 18 of said cable 1,
adapted to hold the cable 1 in a fixed position during processing. The locking device
18 may comprise a pair of elements that are movable between an operational position
of cable locking, in which the cable is retained between the pair of locking elements,
and a non-operational position of releasing the cable. For example, such a locking
device can be configured as a clamp and different actuating modes for locking/releasing
the cable can be employed, such as hydraulic or pneumatic or electric actuators.
[0120] With reference to figures 1A and 1B, in a possible embodiment, the end portion 1a
of the electric cable 1 is typically prearranged by removing a portion of protective
sheathing 6 having given length, so as to expose the shielding braid 4 (if any) of
the end portion 1a of the electric cable 1.
[0121] In the case where the cable 1 has the shielding braid 4, the cable can be prepared
for the subsequent removal of the foil 3 for example by means known in the art, which
overturn the shielding braid 4 and are adapted to fold up the end portion of the shielding
braid in such a way that the end portion of the underlying foil 3 is exposed.
[0122] In a possible embodiment shown in figures 2A and 2B, the exposed part of the shielding
braid 4 is preferably locked by locking means 13 adapted to firmly retain a portion
of the shielding braid 4, and folded, by overturning means to overturn the shielding
braid 4, which are adapted to fold up the end portion 4a of the shielding braid 4
over the locking means 13, so that the end portion 3a of the underlying shielding
foil 3 is exposed. The end portion 1a of the shielded electric cable 1, thus prearranged,
is then ready to undergo the step of removing the end portion 3a of the shielding
foil 3.
[0123] In fact, as a result of overturning the braid, at least one end portion 3a of the
shielding foil 3 is exposed for processing and not covered by the shielding braid
4.
[0124] In a possible embodiment shown for example in figure 3, the apparatus 10 comprises
positioning means 14, 15 to position the shielding foil 3 of the at least one conductor
2, 20 in tensioned position, and radially moving means 9 and axially moving means
9a (schematically shown in figure 8).
[0125] The radially moving means 9 are configured to move the positioning means 14, 15 with
respect to the cable 1, preferably at least along a radial direction with respect
to the longitudinal axis X of the cable 1.
[0126] The axially moving means 9a are configured to operate a relative tensioning motion
in an axial direction with respect to the cable 1, between said positioning means
14, 15 and the cable 1, to accomplish a tensioning stroke to cause the tensioning,
or the tensioning and subsequent removal, of the end portion 3a of the shielding foil
3.
[0127] The radially and axially moving means 9, 9a schematically shown in figure 8 may comprise
one or more actuators of known types, for example of pneumatic, electric or hydraulic
type.
[0128] In particular, the positioning means 14, 15 are moved by the radially moving means
9, preferably in a radial direction with respect to the cable 1, between a closed
position shown in figures 4, 5 and 6 to engage the outer surface of the shielding
foil 3 and an open position shown for example in figures 3, 7 and 8, in which the
cable 1 is released from the cutting means 14, 15.
[0129] In addition, the positioning means 14, 15, after they have been placed in closed
position around the shielding foil, are moved by the axially moving means 9a that
determine a relative motion, preferably in the axial direction, with respect to the
cable 1 (and in particular with respect to the axis X of the cable) to accomplish
a tensioning stroke, to cause tensioning, or tensioning and subsequent removal of
the end portion 3a of the shielding foil 3.
[0130] According to a possible embodiment, the tensioning stroke of the positioning means
14, 15 in an axial direction (i.e., in the direction X' parallel to or coincident
with the axis X of the cable) can be between 0.2 mm and 3 mm. However, other values
of the tensioning stroke are not excluded and can be appropriately selected in relation
to the characteristics of the foil used in the cable being processed, such as the
thickness of the foil and its elasticity.
[0131] Specifically, according to an embodiment, as can be seen for example from the configuration
in figure 4, the axial translation movement in the direction parallel to or coincident
with the axis X of the cable, the positioning means 14, 15 are in contact with the
foil and allow it to be tensioned by applying a tensile force towards the free end
of the cable (towards the left if looking at figure 4).
[0132] For example, the positioning means 14, 15 may comprise two elements that have a main
longitudinal extension direction and comprise respective abutment or contacting surfaces
14a, 15a that, in the closed position of the positioning means 14, 15, form a retaining
and locking surface 140.
[0133] According to an aspect, the end portion 3a of the shielding foil 3 is retained by
the abutment or contacting surfaces 14a, 15a of the positioning means 14, 15 at least
during the tensioning movement of the end portion 3a of the shielding foil 3 and during
the cutting step, i.e., at least when the cutting means are moved closer in the closed
position around the shielding foil.
[0134] According to a preferred embodiment, the relative tensioning motion of the foil is
given by the movement of the positioning means 14, 15 with respect to the cable 1,
which remains in a fixed position, however, embodiments providing the axial movement
of the cable with respect to the positioning means held in a fixed position are not
excluded.
[0135] It should be highlighted that during the axial motion and during the subsequent cutting
step in which the cutting means 8a, 8b reach the closed position around the foil (see
for example figure 5), the end portion 3a of the foil 3 is retained by the positioning
means 14, 15.
[0136] In particular, the end portion of the foil is retained under tension by the positioning
means 14, 15.
[0137] It should be noted that, according to possible embodiments, the contacting surface
14a, 15a with the end part of the shielding foil of the positioning means 14, 15 is
configured to ensure the anchorage and/or an increase in the coefficient of friction
as well as an increase in localized pressure.
[0138] According to possible embodiments, the contacting surface 14a, 15a of the positioning
means 14, 15 comprises a surface discontinuity, e.g. comprises a plurality of recesses
and/or protrusions. In addition or as an alternative, a material can be interposed
between the contacting surface 14a, 15a and the foil (e.g., an insert permanently
or removably constrained to the surface 14a, 15a) that increases the coefficient of
friction thereof, or at least part of the contacting surface 14a, 15a can be made
with a material having high coefficient of friction.
[0139] According to a possible embodiment, as for example shown in the attached figures,
the contacting surface 14a, 15a of the positioning means 14, 15 has a surface discontinuity
comprising a plurality of adjacent recesses, preferably having longitudinal extent
perpendicular to the axis of the cable, thus forming a sawtooth surface pattern, so
as to enable the proper retention of the foil particularly during its tensioning,
which preferably involves subjecting the foil to a tensile action through the contacting
surfaces 14a, 15a of the positioning means.
[0140] As mentioned above, the action of the cutting means 8a, 8b on the foil under tension
allows a clean and precise cut to be achieved.
[0141] In an embodiment, the abutment surfaces 14a, 15a have a non-rectilinear profile comprising
a shaping with indentations of curvilinear or rectilinear conformation, or a combination
thereof.
[0142] When the positioning means 14, 15 are brought to the closed position, the abutment
surfaces 14a, 15a, which preferably have complementary shaping, face each other to
make the locking surface 140 within which the cable 1 is retained.
[0143] According to a possible embodiment for example shown in the attached figures, when
the positioning means are moved towards the closed position in a radial direction
with respect to the cable 1, the abutment surfaces 14a, 15a can at least partially
slide with respect to each other, along a direction substantially parallel to the
main longitudinal extension direction of the positioning means 14, 15 and radial with
respect to the longitudinal axis X of the cable 1.
[0144] As mentioned above, the locking surface 140, made by the facing abutment surfaces
14a, 15a, delimits a section (opening) that is substantially complementary to the
section of the end portion 1a of the cable 1 comprising the end portion 3a of the
shielding foil 3 that covers the at least one conductor 2, 20.
[0145] For example, in the case of a coaxial cable 1, the abutment surfaces 14a, 15a have
a curvilinear portion and the locking surface 140 can be formed as a substantially
circular surface.
[0146] In the embodiment in which the cable 1 to be processed is a cable of the bipolar
type comprising two adjacent conductors 2, 20, the abutment surfaces 14a, 15a have
at least one curvilinear portion (or a combination of curvilinear portions), and the
locking surface 140 formed by the two facing abutment surfaces 14a, 15a is configured
substantially complementary to the profile of the outer surface of the shielding foil
3 covering the adjacent conductors 2, 20, and preferably has either a substantially
circular profile, preferably the profile of the locking surface is formed by the intersection
of two circumferences intersecting each other, or a substantially rectangular profile
(as, for example, can be seen in the embodiment of the attached figures and in particular
in figures 9A, 9B).
[0147] According a possible embodiment, as can be seen for example in figure 9A, 9B, in
the case where the cable 1 is a cable of the bipolar type, the abutment surfaces 14a,
15a have at least one straight portion (or a combination of straight portions), and
the locking surface 140 formed by the two facing abutment surfaces 14a, 15a is configured
to be substantially complementary to the profile of the outer surface of the shielding
foil 3 covering the adjacent conductors 2, 20 and preferably has a substantially rectangular
profile. It should be noted that embodiments in which the abutment surfaces 14a, 15a
of the positioning means 14 comprise a combination of straight and curvilinear portions
are not excluded.
[0148] In the embodiment in which the cable 1 to be processed comprises more than two conductors,
the abutment surfaces 14a, 15a have at least one curvilinear portion (or a combination
of curvilinear portions), and the locking surface 140 formed by the two facing abutment
surfaces 14a, 15a is configured to be substantially complementary to the profile of
the outer surface of the shielding foil 3 that covers the conductors.
[0149] It should be noted, in general, that the abutment surfaces 14a, 15a of the positioning
means are selected and configured such that, once placed in the closed position around
the shielding foil, the tensioning movement (i.e., the relative movement of the positioning
means with respect to the cable) allows at least one tensioning position of the shielding
foil to be reached and in particular allows a tensile action to be provided on the
shielding foil so as to cause it to be tensioned.
[0150] As shown, for example, in figures 3 and 10A, 10B, the apparatus 10 for preparing
an end portion 1a of a shielded electric cable 1, in which the end portion 3a of the
shielding foil 3a is removed, comprises cutting means 8a, 8b provided with a cutting
surface 81a, 81b preferably configured to be substantially complementary to the profile
of the outer surface of the shielding foil 3 covering the at least one conductor 2,
20 and/or to be substantially complementary to the profile of the outer surface of
the covering layer 5, 50 of the at least one conductor 2, 20.
[0151] It should be clarified that, in this document, the "cutting means" terminology denotes
an element (or blade) having a cutting edge or cutting surface, see for example in
figures 10A and 10B the portions denoted by the numerical references 81a, 81b to indicate
the cutting surface or cutting edge.
[0152] Radially moving means 19 are also provided, for example schematically shown in figure
8, configured to move the cutting means 8a, 8b with respect to the cable 1, preferably
at least along a radial direction with respect to the longitudinal axis X of the cable
1 (as, for example, shown in the attached figures).
[0153] The radially moving means 19 of the cutting means 8a, 8b, schematically shown in
figure 8, may comprise one or more actuators of known types, for example of pneumatic,
electric or hydraulic type.
[0154] In a preferred embodiment, the apparatus 10 further comprises axially moving means
7 adapted to operate a relative motion between the cutting means 8a, 8b and the cable
1, in an axial direction with respect to the cable 1, in order to cause the end portion
3a of the shielding foil 3 to be removed.
[0155] It should be noted that the radially moving 9 means and the axially moving 9a means
of the positioning means 14, 15 and the radially moving 19 means and the axially moving
7 means of the cutting means 8a, 8b can be independent and separate from each other,
or according to the invention they can also correspond. In other words, it is also
possible that there are single moving means that determine the movement in radial
and axial directions of the cutting means 8a, 8b and the positioning means 14, 15.
[0156] In particular, according to a possible embodiment (as shown, for example, in the
accompanying figures), the cutting means 8a, 8b are moved by the radially moving means
19, preferably in a radial direction with respect to the cable 1, between a closed
position shown in figures 5, 6 in which the cutting surface 81a, 81b engages the outer
surface of the shielding foil 3, and an open position shown in figure 3 and 7 in which
the cable 1 is released from the cutting means 8a, 8b.
[0157] In the closed position, the cutting surface 81a, 81b of the cutting means 8a, 8b
has a profile substantially complementary to the profile of the end portion 1a of
the cable 1 comprising the end portion 3a of the shielding foil 3 that covers the
at least one conductor 2, 20. The section delimited by the profile of the cutting
surface 81a, 81b of the cutting means 8a, 8b substantially corresponds to the section
of the end portion 1a of the cable 1 (according to a plane perpendicular to the cable
axis X) comprising the end portion 3a of this exposed shielding foil 3 covering said
at least one conductor. As mentioned above, embodiments are not excluded in which
the section delimited by the profile of the cutting surface 81a, 81b of the cutting
means 8a, 8b substantially corresponds to the section of the end portion 1a of the
cable 1 (according to a plane perpendicular to the cable axis X), externally delimited
by the outer surface of the covering layer 5, 50 of the at least one conductor 2,
20 of the cable 1.
[0158] For example, in the case of a coaxial cable 1, the cutting surface 81a, 81b comprises
at least one curved surface. Embodiments in which the cutting surface comprises at
least one straight surface, or a combination of straight and curvilinear surfaces,
are not excluded.
[0159] According to a possible embodiment in which the cable 1 to be processed is a cable
of the bipolar type, comprising two adjacent conductors 2, 20, as for example can
be seen in figures 10A, 10B, the cutting surface 81a, 81b of the cutting elements
8a, 8b is configured to be substantially complementary to the profile of the outer
surface of the cover 5, 50 of the two adjacent conductors 2, 20, and preferably has
a profile formed by the intersection of two circumferences intersecting each other,
as for example shown in figures 10A, 10B.
[0160] In a possible embodiment, the cutting means 8a, 8b comprise two substantially planar
elements (or blades), which have two respective cutting surfaces 81a, 81b made on
respective matching surfaces 82a, 82b.
[0161] In an embodiment, the matching surfaces 82a, 82b have a straight portion and are
adapted to abut against each other in the closed position.
[0162] With reference to figures 3, 10A, 10B, the cutting surfaces 81a, 81b have a cutting
profile of curvilinear shape, which is formed on these matching surfaces 82a, 82b
so that, according to a front view of the cutting elements 8a, 8b (see, for example,
figures 10A, 10B), the cutting surfaces 81a, 81b appear as curvilinear indentations
made along the straight portion of the matching surfaces 82a, 82b.
[0163] In the embodiment shown for example in figure 1C in which the cable comprises two
adjacent conductors 2, 20, the cutting surfaces 81a, 81b have profile formed by the
intersection of two circumferences intersecting each other.
[0164] It should be noted that according to a possible embodiment, as can be seen for example
in figures 10A, 10B, the cutting surfaces 81a, 81b have at least one protruding element
83a, 83b, or protruding tooth, for example made at the intersection of the two circumferences
forming the cutting surface. This protruding element 83a, 83b engages the foil 3,
when the cutting means are in the closed position, and is intended to be inserted
into the space below the foil 3 between the two adjacent conductors 2, 20.
[0165] As shown, for example, in figures 5, 6, 10A, 10B, in the closed position the cutting
elements 8a, 8b join each other so that they fit along their respective matching surfaces
82a, 82b, thus forming a continuous wall which extends around the cutting surface
81a, 81b. For example, the continuous wall can be seen in the front view of figure
10A in which the front parts of the cutting means 8a, 8b are shown. The rear surface
of the cutting means 8a, 8b, that can be seen for example in figure 10B, may have
a lowered surface in the area surrounding the cutting surface, to possibly accommodate
the part of the cable 1 having largest section as it comprise the overturned outer
sheath and braid (if any). According to an aspect of the present invention, the end
portion 3a of the shielding foil 3 is removed by the cutting means 8a, 8b and/or the
positioning means 14, 15, thus by a separate (or simultaneous) action of the cutting
means and the positioning means. In more detail, according to an aspect of the present
invention, the end portion 3a of the shielding foil 3 is removed by the axially moving
means 7 adapted to operate a relative motion between the cutting means 8a, 8b and
the cable 1, preferably in an axial direction with respect to the cable, and/or by
the moving means 9a adapted to operate a relative motion between the positioning means
14, 15 and said cable 1, preferably in an axial direction with respect to the cable.
[0166] In the following, the removal of the foil by moving both the cutting means and the
positioning means will be described with reference to the figures, as stated, this
embodiment should not be understood as limiting and it is also possible to carry out
the removal of the foil by using either the cutting means or the positioning means.
What is described below with reference to the positioning means and the cutting means
also applies to the embodiment in which foil removal is carried out by using only
the positioning means, or only the cutting means, and not their simultaneous action.
[0167] The apparatus 10 according to the invention comprises axially moving means 7 adapted
to operate a relative motion between the cutting means 8a, 8b and the cable 1, preferably
in an axial direction with respect to said cable 1, in order to cause the end portion
3a of the shielding foil 3 to be removed.
[0168] The radially moving means 7 to generate the relative motion between the cable 1 and
the cutting means 8a, 8b, schematically shown in figure 8, may comprise one or more
actuators of known types, for example of pneumatic, electric or hydraulic type.
[0169] It should be noted that the moving means 7 that determine the relative motion between
cable and cutting means may be independent, and therefore separate, from the radially
and axially moving means 9, 9a of the positioning means 14 and 15 and from the radially
moving means 19 of the cutting means 8a, 8b. However, possible embodiments in which
there are single moving means that cause the preferably axial movement of the cutting
means and/or the positioning means 14, 15 with respect to the cable, and likewise
cause the opening/closing movement of the cutting means 8a, 8b and/or the positioning
means 14, 15, are not excluded.
[0170] According to a preferred embodiment shown in figure 6, the relative motion is given
by the movement of the cutting means 8a, 8b with respect to the cable 1, which remains
in a fixed position, however, embodiments providing the axial movement of the cable
with respect to the cutting means 8a, 8b held in a fixed position are not excluded.
[0171] It should be highlighted that, according to a possible embodiment as for example
shown in figure 6, during the axial motion, the end portion 3a of the foil 3 is retained
not only by the positioning means 14, 15 but also by the cutting means 8a, 8b.
[0172] In fact, the moving means 9a of the positioning means 14, 15 previously used to operate
a relative tensioning motion between the positioning means 14, 15 and the cable 1
are further actuated to operate an additional relative motion with respect to the
cable in order to remove the foil.
[0173] According to a preferred embodiment shown in figure 6, the relative motion is given
by the movement of the positioning means 14, 15 with respect to the cable 1, which
remains in a fixed position, however, embodiments providing the axial movement of
the cable with respect to the positioning means 14, 15 held in a fixed position are
not excluded.
[0174] In fact, according to a possible embodiment, after the foil has been tensioned and
cut, the positioning means 14, 15 remain in closed position around the shielding foil
and are further moved by the axially moving means 9a that determine a relative motion,
preferably in axial direction, with respect to the cable 1 (and in particular with
respect to the cable axis X), to cause the end portion 3a of the shielding foil 3
to be removed.
[0175] In fact, according to a possible embodiment, the shielding foil 3 is retained and
then dragged by the wall formed by the cutting means 8a, 8b as a result of the movement,
and is also retained and dragged by the contacting surface 14a, 15a of the positioning
means 14, 15 which remain in the closed position.
[0176] The axial translation of the cutting means 8a, 8b and the positioning means 14, 15
with respect to the cable 1 allows the end portion 3a of the foil 3 retained by the
cutting means 8a, 8b and the positioning means 14, 15 to be removed.
[0177] In addition, if necessary, the radial movement and/or axial movement of the cutting
means 8a, 8b and/or the positioning means 14, 15 can be repeated to finalize the removal
of the end portion 3a of the foil 3.
[0178] It should be noted that the axial movement described is a movement of the cutting
means 8a, 8b and/or the positioning means 14, 15 away from the cable, i.e., towards
the free end of the cable, but it can also provide at least one axial movement of
the cutting means 8a, 8b and/or the positioning means 14, 15 in the opposite direction,
that is to say towards the opposite end of the cable with respect the one undergoing
the operation.
[0179] In a preferred embodiment, the apparatus comprises at least one pressurised air source
11 adapted to deliver pressurised air to the end portion of the foil, such that the
pressurised air exerts a force on the end portion 3a of the shielding foil 3 to push
it towards the cutting surface 81a, 81b of the cutting means 8a, 8b.
[0180] In an embodiment, during the relative motion between the cutting means 8a, 8b and
the cable 1, in an axial direction with respect to the cable 1, the end portion 3a
is retained by the cutting means 8a, 8b and is pushed against the cutting means 8a,
8b by the pressurised air.
[0181] In particular, the pressurised air source 11 preferably comprises a nozzle, for example
connected to a pressurised air line, or to a compressor or tank, and is adapted to
deliver pressurised air to the end portion 1a of the cable 1, such that the pressurised
air exerts a force on the end portion 3a of the at least one shielding foil 3, to
push it towards the cutting surface 81a, 81b of the cutting means 8a, 8b and cause
it to be retained with respect to the surfaces 8a and 8b. As mentioned, the action
of the air may further cause the shielding foil to be partially torn.
[0182] As shown in figure 7A and 7B, the pressurised air pushes the end portion 3a of the
shielding foil 3 towards the cutting means 8a, 8b in the closed position, so that
the end portion 3a is pushed into contact with the cutting surface 81a, 81b.
[0183] Pressurised air is preferably delivered as an air jet with a value between 2 bars
and 80 bars, preference being given to pressures tending towards the higher value.
According to possible embodiments, the delivered air has pressure between 30 bars
and 80 bars, preferably between 40 bars and 80 bars.
[0184] Specifically, in a preferred embodiment, pressurised air is delivered through the
nozzle 11 along an axial direction defined by the longitudinal axis X of the cable
1, to hit the front of the cable 1 and, by creeping between the one or more conductor(s)
2, 20 and the foil 3, pushes the end portion 3a of the foil 3 against the cutting
surface of the cutting elements 8a, 8b thereby ensuring its adhesion and, possibly,
generating its tearing.
[0185] As mentioned above, the direction of the air flow generated by one or more ducts
of the nozzle 11 is not limited to the one axial (parallel or corresponding) to the
longitudinal X axis of the cable but may also comprise angled directions with respect
to the cable axis, preferably in a converging direction with respect to the cable
axis.
[0186] It should also be noted that, during the axial motion, the end portion 3a of the
foil 3 is retained by the cutting means 8a, 8b.
[0187] In fact, as a result of the movement, the shielding foil 3 is retained and then dragged
by the wall formed by the cutting means 8a, 8b.
[0188] In addition, according to a preferred embodiment, not only the pressurised air delivered
by the source 11 opens the foil 3 but it also tends to keep the latter pressed against
the wall formed by the cutting means 8a, 8b, and ensures the retention of the foil
3 against these cutting means 8a, 8b during the axial translation movement of the
cutting means 8a, 8b operated by the axially moving means 7, thereby allowing the
definitive separation of the foil 3.
[0189] In such an embodiment, the axial translation of the cutting means 8a, 8b with respect
to the cable 1 allows the removal of the end portion 3a of the foil 3, which is opened
and retained by the cutting means 8a, 8b and/or the air jet.
[0190] In addition, if necessary, the radial movement and/or the axial movement of the cutting
means 8a, 8b can be repeated to finalize the removal of the end portion 3a of the
foil 3.
[0191] It should be noted that the axial movement described is a movement of the cutting
means 8a, 8b away from the cable, i.e., towards the free end of the cable, but it
can also provide at least one axial movement of the cutting means 8a, 8b in the opposite
direction, that is to say towards the opposite end of the cable with respect the one
undergoing the operation.
[0192] Furthermore, according to this embodiment comprising a pressurised air source 11,
the end portion 3a of the shielding foil 3 is removed by the combined action of the
pressurised air jet and the relative motion operated by the moving means 7 in an axial
direction with respect to the cable 1 between the cutting means 8a, 8b and the cable
1, and/or the relative motion operated by the axially moving means 9a in an axial
direction with respect to the cable 1 between the positioning means 14, 15 and the
cable 1.
[0193] In an embodiment shown in figure 7, the apparatus 10 comprises a suction device 17
for suctioning the end portion 3a which has been torn and removed from the shielding
foil 3.
[0194] In an embodiment, the apparatus 10 comprises a control logical unit configured to
command and control the components of the apparatus, such as the radially moving means
9, 19 to move the positioning means 14, 15 and the cutting means 8a, 8b, respectively,
preferably in the radial direction with respect to the cable 1, particularly between
the open position and the closed position, and the axially moving means 7, 9a to move
the cutting means 8a, 8b and the positioning means 14, 15, respectively, in a preferably
axial direction with respect to the cable 1.
[0195] The following will describe in detail the main steps in the operation of the apparatus
10 according to the present invention for preparing an end portion 1a of a shielded
electric cable 1 by means of an apparatus 10 according to the invention, in which
the outer surface of the end portion 1a has a shielding foil 3 covering at least one
conductor 2, 20 of the cable 1, in which at least one end portion 3a of the shielding
foil 3 is exposed.
[0196] In a possible embodiment, in which the outer surface of the end portion 1a of the
cable 1 has a shielding braid 4 arranged around the shielding foil 3, the process
may comprise a preliminary step shown in figures 2A and 2B and known per se in the
art, in which the end portion 4a of the shielding braid 4 is folded back on itself
by overturning means of the shielding braid 4, so as to expose the end portion 3a
of the underlying shielding foil 3 for processing.
[0197] Specifically, the braid is folded back on itself, that is, its free end is overturned
by 180°.
[0198] In a known manner, locking means 13 adapted to retain the shielding braid 4 may be
applied, and the end portion 4a of the shielding braid 4 is folded back on itself
by means of the overturning means of the shielding braid 4 over these locking means
13, so as to expose the end portion 3a of the underlying shielding foil 3 for processing.
[0199] The process according to the invention comprises a step a), schematically shown for
example in figure 4, of moving the positioning means 14, 15 of the shielding foil
to at least one tensioning position by a relative tensioning motion between the positioning
means and the cable.
[0200] It should be noted that in this step a), the positioning means 14, 15 are moved by
means of the axially moving means 9a described above, which are adapted to operate
a relative tensioning motion in the axial direction with respect to the cable 1, between
the positioning means 14, 15 and the cable 1 to accomplish a tensioning stroke, in
order to cause the tensioning, or the tensioning and subsequent removal, of the end
portion 3a of the shielding foil 3.According to an embodiment, this step is preceded
by the step a') in which the positioning means 14, 15 are moved towards the shielded
electric cable 1 in a radial direction with respect to the longitudinal axis X of
the cable 1, until a closed position of the positioning means 14, 15 around the at
least one shielding foil 3 is reached.
[0201] It should be noted that in this step a') the positioning means 14, 15 are moved by
the axially moving means 9 described above, which are configured to move the positioning
means 14, 15 along a radial direction with respect to the longitudinal axis X of the
cable 1, between a closed position to engage the outer surface of the shielding foil
3 of the cable 1 and an open position in which the cable 1 is released from the positioning
means 14, 15.
[0202] According to a possible embodiment, the step a) of tensioning the foil provides for
operating a relative motion between the positioning means 14, 15 placed in the closed
position around the shielding foil 3, and the cable 1, in the axial direction with
respect to the cable 1, to determine that a foil tensioning position is reached.
[0203] Specifically, the step a) provides for moving the positioning means 14, 15 in the
axial direction with respect to said cable 1 at least towards the free end of the
cable so as to determine the tensioning of the shielding foil, in particular by applying
a tensile force on the foil itself by means of the axially positioning means 9a which
are displaced, preferably axially with respect to the cable.
[0204] The movement described is preferably a movement of the positioning means 14, 15 away
from the cable, that is, towards the free end of the cable.
[0205] The method comprises the further step b), schematically shown for example in figure
5, of moving the cutting means 8a, 8b towards the shielded electric cable 1, preferably
in a radial direction with respect to the longitudinal axis X of the cable 1, until
reaching the closed position of the cutting means 8a, 8b around the shielding foil
3 which is tensioned by the positioning means, so that the cutting surface 81a, 81b
surrounds and/or engages the outer surface of the foil 3 covering the at least one
conductor 2, 20 to carry out the cutting thereof.
[0206] It should be noted that in this step b), the cutting means 8a, 8b are moved by the
above described radially moving means 19 configured to move the cutting means 8a,
8b, along a radial direction with respect to the longitudinal axis X of the cable
1, with respect to the foil placed in a tensioning position to carry out the cutting
of the foil.
[0207] In addition, according to an aspect, the method according to the invention comprises
a step c) schematically shown in figure 6, of operating a relative motion between
the cutting means 8a, 8b and/or the positioning means 14, 15 placed in a closed position
around the shielding foil 3, and the cable 1, in a preferably axial direction with
respect to the cable 1, to cause the end portion 3a of the shielding foil 3 to be
removed.
[0208] It should be noted that in this step c) the positioning means 14, 15 are moved by
the axially moving means 9a described above, which are adapted to operate a relative
motion in the axial direction with respect to the cable 1, between the positioning
means 14, 15 and the cable 1 to cause the removal of the end portion 3a of the shielding
foil 3, and the movement of the cutting means 8a, 8b is operated by the axially moving
means 7 described above, which are adapted to operate a relative motion between the
cutting means 8a, 8b and said cable 1, in the axial direction with respect to the
cable 1, to cause the removal of the end portion 3a of the shielding foil 3.
[0209] In particular, the step c) provides for moving the cutting means 8a, 8b and/or the
positioning means 14, 15 in an axial direction with respect to said cable 1, at least
towards the free end of the cable.
[0210] The axial movement described is a movement of the cutting means 8a, 8b and/or the
positioning means 14, 15 away from the cable, i.e., towards the free end of the cable,
but it can also provide at least one axial movement of the cutting means 8a, 8b and/or
the positioning means 14, 15 in the opposite direction, that is to say towards the
center of the cable 1.
[0211] It should be noted that, according to an embodiment, in the step c) the positioning
means 14, 15 are also held in the closed position around the cable and thus this step
also simultaneously comprises moving the positioning means (at the same time as the
cutting means 8a, 8b), preferably in the axial direction, with respect to said cable
1 at least towards the free end of the cable.
[0212] The axial movement described is a movement of the cutting means 8a, 8b and/or the
positioning means 14, 15 away from the cable, i.e., towards the free end of the cable,
but it can also provide at least one axial movement of the cutting means 8a, 8b and/or
the positioning means 14, 15 in the opposite direction, that is to say towards the
center of the cable 1.
[0213] In an embodiment, the process provides the further step, schematically shown in figure
7, of moving the cutting means 8a, 8b with respect to the shielded electric cable
1, in a radial direction with respect to the longitudinal axis X of the cable 1, until
an open position of the cutting means is reached in which the cable 1 is released
from the cutting means 8a, 8b.
[0214] In an embodiment, wherein the apparatus 10 comprises at least one pressurised air
source 11 adapted to deliver pressurised air towards the end portion 1a such that
the pressurised air exerts a force on the end portion 3a of the shielding foil 3 to
push it towards the cutting surface 81a, 81b of the cutting means 8a, 8b, the method
further comprises the step (d), shown for illustrative purposes in figures 7A and
7B, of delivering pressurised air by means of the pressurised air source 11 towards
the end portion 1a of the cable 1, such that the pressurised air exerts a force on
the end portion 3a of the shielding foil 3 to push it towards the cutting surface
81a, 81b of the cutting means 8a, 8b and causing it to be partially torn.
[0215] Preferably, the pressurised air is delivered through the nozzle 11 along an axial
direction (as mentioned, different directions of the air flow are not excluded) defined
by the longitudinal axis X of the cable 1, to hit the front of the cable 1 and, by
creeping between the one or more conductor(s) 2, 20 and the foil 3, pushes the end
portion 3a of the foil 3 against the cutting surface of the cutting elements 8a, 8b
thereby generating its retention and, possibly, tearing.
[0216] In an embodiment, at least part of the step (c) described above and schematically
shown in figure 8, during which a relative motion is operated between the cutting
means 8a, 8b placed in the closed position around the shielding foil 3, and the cable
1, in the axial direction with respect to the cable 1 in order to cause the removal
of the end portion 3a of the shielding foil 3, is carried out during step (d), i.e.,
the axial movement of the cutting means 8a, 8b to the closed position around the cable
1 occurs at least in a part, and preferably for the entire duration, while pressurised
air is delivered from the nozzle 11 towards the front of the cable 1.
[0217] In particular, the step (c) provides for moving the cutting means 8a, 8b in an axial
direction with respect to the cable 1 at least in the direction opposite the delivery
direction of pressurised air delivered by the pressurised air source 11.
[0218] The axial movement described is a movement of the cutting means 8a, 8b away from
the cable, i.e., towards the free end of the cable, but at least one axial movement
of the cutting means 8a, 8b in the opposite direction, that is to say towards the
center of the cable 1, may also be provided.
[0219] At the end of step c) the process may comprise the further step, schematically shown
for example in figure 7, of moving the positioning means 14, 15 with respect to the
shielded electric cable 1, in a radial direction with respect to the longitudinal
axis X of the cable 1, until an open position is reached in which the cable 1 is released
from the positioning means 14, 15.
[0220] In an embodiment, the process provides the further step, schematically shown in figure
7, of moving the cutting means 8a, 8b with respect to the shielded electric cable
1, in a radial direction with respect to the longitudinal axis X of the cable 1, until
an open position of the cutting means is reached in which the cable 1 is released
from the cutting means 8a, 8b.
[0221] Next, the process comprises an additional step, for example shown in figure 7, of
suctioning the end portion 3a removed from the shielding foil.
1. Apparatus (10) for removing an end portion (3a) of the shielding foil (3) of a shielded
electric cable (1), wherein an end portion (1a) of said cable (1) has at least one
shielding foil (3) which covers at least one conductor (2, 20) equipped with a covering
layer (5, 50), wherein at least one end portion (3a) of said shielding foil (3) is
exposed, said apparatus (10) comprising:
- positioning means (14, 15) for positioning said shielding foil (3) of said at least
one conductor (2, 20) in at least one tensioning position,
- moving means (9a) adapted to operate a relative tensioning motion in an axial direction
with respect to said cable (1), between said positioning means (14, 15) and said cable
(1), to cause the tensioning of said end portion (3a) of the shielding foil (3),
- cutting means (8a, 8b) provided with a cutting surface (81a, 81b) and moving means
(19) configured to move said cutting means (8a, 8b), preferably at least along a radial
direction with respect to the longitudinal axis (X) of said cable (1), with respect
to said foil placed in a tensioning position to carry out the cutting of the foil.
2. Apparatus according to claim 1, characterized in that it comprises moving means (9) configured to move said positioning means (14, 15)
with respect to said cable (1), preferably at least along a radial direction with
respect to the longitudinal axis (X) of said cable (1), between a closed position
to engage the outer surface of said shielding foil (3) of said cable (1) and an open
position in which said cable (1) is released from said positioning means (14, 15).
3. Apparatus according to claim 2, wherein in said closed position the contacting surface
(14a, 15a) of the shielding foil of the positioning means (14, 15) with the end portion
(3a) delimits an opening (140) substantially complementary to the section of the end
portion (1a) of the cable (1) comprising the end portion (3a) of the shielding foil
(3) which covers the at least one conductor (2, 20), and wherein preferably the contacting
surface (14a, 15a) of the positioning means (14, 15) is configured to ensure the anchorage
and/or an increase in the coefficient of friction, preferably the contacting surface
(14a, 15a) contacting the end portion (3a) comprises a surface discontinuity and/or
a high coefficient of friction material.
4. Apparatus according to any one of the preceding claims, wherein said moving means
(9a) cause a relative motion, preferably in an axial direction with respect to said
cable (1), between said positioning means (14, 15) and said cable (1) to cause the
tensioning, or the tensioning and subsequent removal, of said end portion (3a) of
the shielding foil (3).
5. Apparatus according to any one of the preceding claims, wherein said positioning means
(14, 15) are displaced by said moving means (9a) by a tensioning stroke, preferably
between 0.2 mm and 3 mm, to cause the tensioning of said end portion (3a) of the shielding
foil (3).
6. Apparatus according to any one of the preceding claims, wherein said positioning means
(14, 15) are displaced by said moving means (9a) by a further stroke, greater than
said tensioning stroke, to cause the removal of said end portion (3a) of the shielding
foil (3).
7. Apparatus according to any one of the preceding claims, wherein said cutting surface
(81a, 81b) of said cutting means (8a, 8b) has a profile substantially complementary
to the profile of the outer surface of said shielding foil (3) and/or the profile
of the outer surface of the covering layer (5, 50) of said at least one conductor
(2, 20), wherein preferably said cutting surface (81a, 81b) of said cutting means
(8a, 8b) comprises at least one curved surface, and/or wherein said cutting surface
(81a, 81b) has a profile substantially formed by the intersection of two circumferences
intersecting each other and preferably said cutting surface (81a, 81b) comprises at
least one protruding element, or tooth (83a, 83b).
8. Apparatus (10) according to any one of the preceding claims, wherein said cutting
means (8a, 8b) are moved by means of said moving means (19), preferably in a radial
direction with respect to said cable (1), between a closed position in which said
cutting surface (81a, 81b) engages the outer surface of said shielding foil (3), and
an open position in which said cable (1) is released from said cutting means (8a,
8b).
9. Apparatus according to one of the preceding claims, comprising moving means (7) adapted
to operate a relative motion between said cutting means (8a, 8b) and said cable (1),
preferably in an axial direction with respect to said cable (1).
10. Apparatus according to one of the preceding claims, wherein said end portion (3a)
of the shielding foil (3) is retained by said positioning means (14, 15) at least
during the tensioning movement of said end portion (3a) of the shielding foil (3)
and during the cutting step, and wherein said end portion (3a) of said shielding foil
(3) is removed by said cutting means (8a, 8b) and/or said positioning means (14, 15).
11. Apparatus according to one of the preceding claims, comprising at least one pressurised
air source (11) adapted to deliver pressurised air to said end portion (1a), in such
a way that the pressurised air exerts a force on said end portion (3a) of said at
least one shielding foil (3) to push it towards said cutting surface (81a, 81b) of
said cutting means (8a, 8b);
12. Apparatus according to claim 11, wherein said pressurised air source (11) delivers
air at a pressure between 2 bars and 80 bars, preferably between 30 bars and 80 bars,
more preferably between 40 bars and 80 bars.
13. Apparatus according to claim 11 or 12, wherein during said relative motion between
said cutting means (8a, 8b) and said cable (1), in an axial direction with respect
to said cable (1), said end portion (3a) is retained by said cutting means (8a, 8b)
and is pushed against said cutting means (8a, 8b) by the pressurised air.
14. Apparatus according to any one of claims 11 - 13, wherein said end portion (3a) of
said shielding foil (3) is removed by the combined action of said pressurised air
jet and said relative motion operated by said moving means (7) in an axial direction
with respect to said cable (1) between said cutting means (8a, 8b) and said cable
(1), and/or by said relative motion operated by said moving means (9a) in an axial
direction with respect to said cable (1) between said positioning means (14, 15) and
said cable (1).
15. Apparatus (10) according to any one of the preceding claims, wherein said cutting
means (8a, 8b) in said closed position form a continuous wall extending around said
cutting surface (81a, 81b).
16. Process for removing an end portion (3a) of the shielding foil (3) of a shielded electric
cable (1) by means of an apparatus (10) according to one of the preceding claims,
wherein said end portion (1a) has a shielding foil (3) which covers at least one conductor
(2, 20) equipped with a covering layer (5, 50), wherein at least one end portion (3a)
of said shielding foil (3) is exposed, said process comprising the following steps:
a) moving said positioning means (14, 15) of said shielding foil (3) of said at least
one conductor (2, 20) into at least one tensioning position, by means of a relative
tensioning motion in an axial direction with respect to said cable (1) between said
positioning means (14, 15) and said cable (1) to cause the tensioning of said end
portion (3a) of the foil;
b) moving said cutting means (8a, 8b) towards said shielded electric cable (1), preferably
in a radial direction with respect to the longitudinal axis (X) of said cable (1),
until a closed position of said cutting means (8a, 8b) around said foil (3) in a tensioned
position is reached, in such a way that said cutting surface (81a, 81b) surrounds
and/or engages the outer surface of said foil (3) covering said at least one conductor
(2, 20) to carry out the cutting of the foil.
17. Process according to claim 16, wherein said apparatus (10) comprises moving means
(7) adapted to operate a relative motion between said cutting means (8a, 8b) and said
cable (1), in an axial direction with respect to said cable (1), to cause said end
portion (3a) of said shielding foil (3) to be removed, and said process comprises
the step c) of operating a relative motion between said cutting means (8a, 8b) placed
in a closed position around the shielding foil (3) and said cable (1), preferably
in an axial direction with respect to said cable (1) to cause said end portion (3a)
of said at least one shielding foil (3) to be removed and/or the step of operating
a relative motion between said positioning means (14, 15) and said cable (1), preferably
in an axial direction with respect to said cable (1), to cause said end portion (3a)
of said at least one shielding foil (3) to be removed.
18. Process according to claim 16 or 17, wherein said apparatus (10) comprises at least
one pressurised air source (11) adapted to deliver pressurised air towards said end
portion (1a), in such a way that the pressurised air exerts a force on said end portion
(3a) of said at least one shielding foil (3) to push it towards said cutting surface
(81a, 81b) of said cutting means (8a, 8b) and said process comprises the step (d)
of delivering pressurised air by means of said pressurised air source (11) towards
said end portion (1a) of said cable (1), in such a way that the pressurised air exerts
a force on said end portion (3a) of said shielding foil (3) to push it towards said
cutting surface (81a, 81b) of said cutting means (8a, 8b), thereby ensuring adhesion
of the shielding foil (3) against the surface of the cutting means (81a, 81b)
19. Process according to claim 18, wherein at least part of said step (c) is carried out
during said step (d).
20. Process according to claim 18 or 19, wherein said step (c) provides for moving said
cutting means (8a, 8b) in an axial direction with respect to said cable (1) at least
in the direction opposite the delivery direction of pressurised air delivered by said
pressurised air source (11), and where preferably said step c) provides for moving
said cutting means (8a, 8b) and/or said positioning means (14, 15), preferably in
an axial direction with respect to said cable (1), at least towards the free end of
the cable.
21. Process according to any one of claims 16 to 20, wherein said step a) provides for
moving said positioning means (14, 15) by a tensioning stroke of the foil, preferably
between 0.2 mm and 3 mm.